Every year for well over a decade (if I am not mistaken) I have renewed the same two policies for the same two properties with the same insurance outfit. Every year the process starts with them sending me a renewal notice for each policy stating a noticeable increase in premium. Every year I phone them and protest/query the premium. Every year I end up with a very modest increase - that is why I am still with them. It seems to me that the "system" (for which read "the computer/software") is rigged to try it on and when you challenge them the premium is adjusted down. Being rather cynical toward insurance companies, I would not be surprised if this was standard practice.
Something else that is standard practice and foreigners I know find really strange, is to base the premium mostly on the number of bedrooms. This way you could easily pay more for insuring a 70m² dwelling with four (mostly very small) bedrooms than a 110m² one with two or three (good ones). Elsewhere it is the norm to base the premium on the total floor area (trust the foreigners to be illogical).